1. Field of the Invention
This invention relates to a cooking appliance, and, in particular, to a cooking appliance that is capable of rapidly toasting bread products, such as muffins, bagels and the like. The cooking appliance is also capable of heating other food products, such as, meats, vegetables and/or garnishes.
2. Description of the Prior Art
In the fast food industry, there is an on going need for high quality toasting of bread products with faster cooking times. One type of prior art toaster used in the fast food industry is a contact toaster. An example of a contact toaster is shown in U.S. patent application Ser. No. 09/257,149, filed on Feb. 24, 1999, assigned to the same assignee as this application, now U.S. Pat. No. 5,983,785, granted Nov. 16, 1999. This patent discloses a contact toaster in which a bread product is conveyed by a conveyor belt in pressure contact with a surface of a heated stationary platen. Contact toasters generally toast only one surface of a bread product, such as the surface that is pressured against the heated platen. Such contact toasters require a relatively long time to achieve high quality toasting of a bread product, such as a bagel or muffin. Increasing the speed of the conveyor belt and increasing temperature of the platen may decrease toasting time, but could burn the food product or produce product low in temperature.
An example of a non-contact toaster is the common household toaster that uses two electrical heater elements on either side of a slot that holds the bread product. Non-contact toasters of this type toast the opposed generally flat surfaces of a bread product. Such toasters generally include a rheostat control that allows regulation of the heater element temperature so that the temperature can be increased or decreased depending on the product being toasted. For example, the temperature may be increased to obtain better and faster toasting for a thick bread product, such as a muffin or a bagel. Frequently, the temperature for a desired toasting time is so hot that the bread product burns.
Tunnel ovens that use air impingement heating are known for cooking a broad range of food products, including pizza. An example of a tunnel ovens shown in U.S. Pat. No. 4,873,107. This patent discloses a pair of oppositely rotating conveyor belts arranged to form a gap along a cooking path. Separate heated air manifolds are positioned with each conveyor belt for directed pressurized hot air on the upper and lower surfaces of a pizza item conveyed along the cooking path in the gap. A tunnel oven of this type is capable of cooking a food product at high temperature in a short time without burning. However, the cooked food product ma lack the crunchiness of a toasted food product.
Thus, there is a need for a toaster that can achieve high quality and faster toasting without burning and still provide the crunchiness of a toasted bread product.
The present invention provides a cooking appliance that meets the aforementioned need for faster toasting/cooking without burning and still providing crunchiness.
The present invention provides a cooking appliance that heats food products and garnishes.
A cooking appliance according to the present invention includes a housing having an inlet and an outlet. A toasting/cooking passageway is defined within the housing. A conveyor assembly moves food products inserted at the inlet along the toasting/cooking passageway. A heated air impingement assembly is arranged to deliver to a top surface of the food product hot air for heating the food product as well as for browning the top surface. An electrical heater is located below the passageway for delivering to a bottom surface of the food product heat and infrared energy. After toasting/cooking, the food products are delivered to the outlet.
The hot air has a temperature that rapidly heats the food product to a toasting temperature in less than 60 seconds. The hot air provides a temperature environment that facilitates the infrared heat to produce a crunchiness effect of the bottom and side surfaces of the food product by the end of the rapid toasting time.
The conveyor assembly has a conveyor belt loop that is spaced from the heated air impingement assembly by a gap. The passageway is located in the gap. An adjustment feature allows the air impingement assembly to be raised and lowered to vary its distance above the food product and thus vary the hot air velocity at the point of impingement.
Another feature is that the heated air impingement assembly and the electrical heater assembly can be structured to provide two or more toasting/cooking areas along the passageway so that different toasting/cooking temperatures and air velocities can be employed.
In alternate embodiments, the conveyor belt assembly has a pair of side by side lower belt loops that form side by side passageways with the air impingement assembly. This allows each passageway to be set for concurrent toasting/cooking of food products of different thickness. Alternatively, the passageway gaps can be the same so as to double the toasting/cooking capability of same thickness food products.
In an alternate embodiment heated impingement air is also delivered from below the food product. The electrical heating assembly is disposed relative to columns of the heated impingement air so that there is no substantial interference between the infrared energy and the impingement air.